/**
 * 接口方式和抽象类写法类似 abstract
 *  类实现 implements
 */

//接口
abstract class A {
  void info();
}

abstract class B {
  void swim();
}

abstract class C {
  void show();
}

class User implements A, B, C {
  @override
  void info() {}

  @override
  void show() {}

  @override
  void swim() {
    // TODO: implement swim
  }
}


void main(){
  var m =User();
  m.show();
  m.info();
}